Work in our laboratory is primarily in the area of glycoprotein synthesis. We have made the rather surprising discovery that a single lipid-linked oligosaccharide serves as the general precursor of all asparagine-linked glycopeptides. We have studied the pathway of synthesis of this lipid linked oligosaccharide and have examined the regulation of its synthesis by pulse-chase experiments. We have also investigated the intracellular site of synthesis of the oligosaccharide and the site of its transfer to nascent polypeptide chains. In addition, we have considered the processing reactions that occur to glycoproteins following their synthesis. Known glycoprotein processing reactions include polypeptide chain cleavage, addition of fatty acyl groups, and processing of oligosaccharide carbohydrate. Finally, changes in glycosylation patterns associated with expression of particular cell surface antigens, with developmental changes in Dictyostelium, and with transformation have also been investigated.